Rotor assembly



3, 1966 L. CHIANG ETAL 3,267,562

ROTOR ASSEMBLY Filed April 29. 1963 BY /V0//27a/2 Gray/and;

zfzzz United States Patent 3,267,562 ROTOR ASSEMBLY Louis Chiang and Norman Casagrande, Wellsville, N.Y., assiguors, by mesne assignments, to The Air Preheater Company, Inc., a corporation of Delaware Filed Apr. 29, 1963, Ser. No. 276,296 Claims. (Cl. 29-1573) The present invention relates to a rotary regenerative heat exchange apparatus and particularly to an improved arrangement and procedure for assembling an element carrying rotor whereby it may be easily transported to and accurately assembled at a given construction site.

Rotary regenerative heat exchange apparatus of the conventional type comprises a rotor having a central rotor post and a concentric rotor shell joined by radial partitions to form sectoral compartments carrying heat absorbent material in the form of metallic plates which are first positioned in a hot gas stream to absorb heat therefrom and then moved into a cool air stream to transfer the absorbed heat thereto. The rotor is surrounded by a housing having end plates formed with openings arranged to direct the flow of the hot gas and cool air alternately through the heat absorbent material in order that heat from the hot gas may be transferred to the cool air through the intermediary of the heat absorbent element. To preclude leakage of fluid from one duct to the other through the clearance space between the rotor and the rotor housing, the end edges of the rotor are customarily provided with sealing means that conform to the variations in the clearance space therebetween.

The rotor of such heat exchange apparatus that is commonly used in modern practice often assumes massive proportions that preclude its being shipped from manufacturing plant to erection site as a complete unit. On occasions where size dictates, the cylindrical rotor is necessarily divided into sections that comprise the cylindrical rotor split along its radius into two or more generally equal prefabricated sections, with the total of the sections to- I gether comprising a cylinder of 360. When the rotor is merely split along its diameter into two sections of 180 assembly presents no special problem, and the two parts may be readily combined at the erection site into a cylindrical rotor. With increasing sizes of such equipment, however, the tendency has been to divide the rotor into eight, ten, twelve or more equal parts whose assembly is more difficult and the resultant rotor less accurate.

In practice, it has been found that assembly of multiple parts is difiicult and that even slight variation in size, shape or assembly procedure often results in a rotor which is not round, not properly balanced, too heavy or otherwise unsatisfactory from an operational standpoint.

The principal object of this invention therefore is to provide an arrangement for manufacturing and assembling the component parts of a rotor whereby they may be easily transported and then readily and accurately assembled at a predetermined erection site into a cylindrical rotor.

Other objects and advantages of the present invention and the manner in which it may be carried into practice will become more apparent upon consideration of the following description and drawings thereof which involve the principles of the invention. Reference is accordingly made to the following drawings in which:

FIGURE 1 is a sectional elevational of a horizontal rotary heat exchanger involving the invention.

FIGURE 2 diagrammatically illustrates the positioning of the prefabricated rotor components on a rotor post, and

FIGURE 3 is a perspective view illustrating the arrangement of constituent parts in a rotor constructed according to the invention.

In the drawings the rotor comprises essentially a central rotor post 12 having support trunnions 14 at opposite ends thereof adapted for rotary movement within suitable bearing structure 15. The rotor post is provided with a series of integral ribs 16 evenly spaced and extending axially about its outer surface to provide points of support for the rotor structure in the form of radial partitions or diaphragms 22 that are formed as walls of sector shaped rotor compartments 24.

Each rotor component 24 preferably includes three radial partitions 22 spaced apart to form a pair of similar sectoral rotor compartments 26 with a common partition therebetween. Each rotor compartment 26 is divided into upper and lower sections by element support grids 28 that are adapted to support the mass of heat absorbent element that is carried in the compartments of the rotor.

An arcuate plate 32 on the rotor circumference is formed to fit the space between the uppermost parts of the two adjacent radial partitions 22 as a structural support member. An arcuate plate 33 continuing axially therefrom is used to fully enclose the periphery of the rotor to preclude the flow of fluid radially through the ends of the compartments. In the preferred embodiment illustrated, the portion of each compartment lying adjacent the cold end of the heat exchanger between the arcuate support plates 32A and 32B is enclosed by a separate closure plate 35 that may be removed without disturbing the plate 33. Thus corroded or plugged heat ab sorbent element carried at the cold end of the rotor may be readily removed and replaced without otherwise disturbing the element carried at the axially spaced end of the rotor.

The heat absorbent element of each compartment is supported at its axially spaced ends by grid members 28 so constructed that they adequately support the heat absorbent element without significantly retarding the flow of fluid therethrough.

In practice, the rotor post 12, the trunnions 14, rotor compartments 24, grids 28 and other rotor structure may be shipped disassembled to the erection site. The rotor post is mounted either horizontally or vertically on suitable bearings -15 to support the rotor in its proper disposition. A single rotor component 24 is secured to the aligned ribs 16 along a line extending axially at the innermost end of each radial partition 22. The component 24 is first secured temporarily with bolts 34 and then made permanent by welding. I 7

After a single component 24 has been secured to the axial ribs 16, an independent grid 36 is installed in the space adjacent thereto in circumferential alignment with each of the element support grids 28 within the prefabricated compartment 24 and secured to the free side of radial partition 22. The grids are positioned by blocks 38 located at the time the compartment 24 is prefabricated. The radially unsupported side of each independent grid 36 may be temporarily supported by axial bracing (not illustrated) that is removed upon completion of the rotor structure.

A second prefabricated rotor component- 24 is then positioned adjacent the radially unsupported sides of the independent grid members 36, and as with the first com ponent 24, the radial partitions 22 are secured at their innermost ends to the radial ribs 16 While their free sides are secured to the unsupported edges of independent grid members 36. After the second rotor component 24 is thus secured, a set of independent grid members 36 is secured to the free side of radial partition 22 in the manner previously defined. Alternating components 24 and sets of independent grid members 36 are installed until a single sectoral space 30 lies open between the first and last installed prefabricated rotor component 24.

Inasmuch as the size of the last spacing 30 lying between adjacent rotor components 24 may vary in accordance with slight difierences in the size and installation of each rotor component 24 and independent grid member 36, it is necessary that an arrangement be available whereby the last spacing 30 may be readily supplied with an independent grid of the proper size. Here the sectoral shape of the spacing between compartments and the similar shape of the grids 36 provide an ideal arrangement wherebythe grid may be axially positioned and. then moved radially into the spacing until its lateral sides abut the sides of the partitions 22 that provide walls for their respective compartments. When the sides of the grid snugly abut thespaced partitions, they are secured thereto in the manner of the other grid members so as to form a completed cylindrical rotor.

After the rotor has been formed as a cylindrical body that comprises a series of compartments with openings in their radially outer ends, each compartment is loaded with heat absorbent element through said openings. To effectively perform this operation, the rotor housing that surrounds the rotor is preferably supplied with an opening (not illustrated) through which the heat absorbent element may be inserted when the rotor is slowly rotated about its axis.

After the prefabricated compartments 24 and the intermediate compartments 30 have been filled with heat absorbent element, arcuate closure plates 33 and 35 are fitted to the radial outer end of each compartment to close its periphery into a composite cylindrical rotor shell that encloses the rotor. Since all compartments 24 and all intermediate compartments 30, except perhaps the last one formed, are similar in size, the closure plates used at these locations may be of a common size. For the final compartment 30 formed the size may vary somewhat; however, merely moving an arcuate closure plate radially until it abuts the sides of radial partitions 22 will compensate for minor variations. In extreme cases where the variation in compartment size may be considerable, suitable shims may be inserted between the edges of the closure plates and adajcent partitions 22. The closure plates 33 and 35 may then be secured to the compartment walls (diaphragms 22) in any suitable manner that precludes leakage of fluid therethrough.

Thus, although the actual dimensions of the parts that comprise the rotor may vary to a small degree, the rotor may be readily assembled from prefabricated parts at the erection site. Moreover, even if small variations in manufacturing the rotor compartments or assembling them into a composite rotor occur, they do in no way preclude or even retard the assembly of the rotor.

We claim:

1. The method of manufacturing a cylindrical rotor for a rotary regenerative heat exchanger that comprises the teps of forming a plurality of sector shaped rotor compart' ments, forming a plurality of sector shaped grid members, and arranging the rotor compartments and grid members alternately about a central rotor post in lateral juxtaposition and securing them thereto to provide a continuous series of sectoral compartments with radial walls therebetween extending outward from the rotor post.

2. The method of making a cylindrical rotor for a iii.

rotary regenerative heat exchanger that comprises the steps of forming a plurality of sector shaped rotor compartments, forming a plurality of sector shaped grid members, arranging the rotor compartments and grid members alternately about a central rotor post and securing them thereto to provide a series of compartments having radial walls carried by the rotor post, and inserting closure means between outboard ends of adjacent radial walls to enclose the rotor in a cylindrical shell concentriowith the rotor post.

3. The method of making a cylindrical rotor for a rotary regenerative heat exchanger that comprises the steps of forming a plurality of sector shapedrotor compartments having imperforate radial walls, forming a series of sector shaped grid members, arranging the rotor compartments and grid members alternately about a central rotor post, securing the radial walls of said compartments to the rotor post and supporting the grid members on the radial walls to provide a cylindrical framework integral therewith, and joining the outer ends of adjacent compartrnents with arcuate members that combine with areaate ends of said rotor compartment to form an annular rotor shell concentric with the rotor post.

4. The method of making a cylindrical rotor for a rotary regenerative heat exchanger that comprises the steps of forming a plurality of sector shaped rotor compartments having imperforate radial Walls, forming a series of sector shaped grid members, arranging the rotor compartments and grid members alternately about a central rotor post, securing the imperforate walls of said rotor compartment to the rotor post, securing theradial walls of the grid members to the imperforate walls of the rotor compartments, and joining the outer ends of said com partments with arcuate plate memebrs that combine to form an annular rotor shell concentric with the rotor post.

5. The method of forming a cylindrical rotor for a rotary regenerative heat exchanger that comprises the steps of forming a series of sector shaped rotor compartments, forming a series of sector shaped grid members, arranging the rotor compartments and grid members alternately about a central rotor post to provide a composite body surrounding the rotor post, and moving selected grid members radially into lateral abutment with the walls of adjacent rotor compartments and securing them thereto whereby the rotor compartments and grid members may be together joined to the rotor post to provide a composite body integral therewith.

References Cited by the Examiner UNITED STATES PATENTS 1,859,573 5/1932 Riley 165-4 FOREIGN PATENTS 740,506 11/1955 Great Britain.

JOHN F. CAMPBELL, Primary Examiner.

WHITMORE A. WILTZ, I. D HOBART,

Assistant Examiners. 

1. THE METHOD OF MANUFACTURING A CYLINDRICAL ROTOR FOR A ROTARY REGENERATIVE HEAT EXCHANGER THAT COMPRISES THE STEPS OF FORMING A PLURALITY OF SECTOR SHAPED ROTOR COMPARTMENTS, FORMING A PLURALITY OF SECTOR SHAPED GRID MEMBERS, AND ARRANGING THE ROTOR COMPARTMENTS AND GRID MEMBERS ALTERNATELY ABOUT A CENTRAL ROTOR POST IN LATERAL JUXTAPOSITION AND SECURING THEM THERETO TO PROVIDE A CONTINUOUS SERIES OF SECTORAL COMPARTMENTS WITH RADIAL WALLS THEREBETWEEN EXTENDING OUTWARD FROM THE ROTOR POST. 